1. Field of the Invention
The present invention relates to a vehicle lamp in which an irradiation direction is adjustable in a horizontal direction and a vertical direction that are orthogonal to each other.
2. Related Art
There is a vehicle lamp which can adjust an irradiation direction in a horizontal direction and in a vertical direction according to a running condition of the vehicle.
For example, in an automotive headlamp, there is a case where the irradiation direction is too upward or too downward depending on a load. In such the case, it is necessary to change the irradiation direction in the downward direction or in the upward direction timely to correctly make the irradiation direction. Further, in case that the vehicle runs on a zigzag road or turns an intersecting point, it is convenient that the irradiation direction can be changed to the left or right in order to illuminate quickly a road surface in the running direction of the vehicle.
For example, in a vehicle lamp described in JP-A-2005-119463, to achieve the above object, there are provided an actuator for rotating a lamp unit in the horizontal direction and another actuator for tilting the lamp unit in the vertical direction.
Further, in a vehicle lamp described in JP-A-2005-186731, to achieve the above object, there is provided a double axis actuator in which an actuator for rotating a lamp unit in the horizontal direction and another actuator for tilting the lamp unit in the vertical direction are built in a single housing, and output parts of these actuators are respectively coupled to separate portions of the lamp unit.
Further, in a vehicle lamp described in JP-A-2003-054310, to achieve the above object, a single drive part and a single output part are provided, and the output part acts on worked parts of the lamp unit that are different from each other.
In the vehicle lamp described in JP-A-2005-119463, there are separately provided the actuator for rotating the lamp unit in the horizontal direction and another actuator for tilting the lamp unit in the vertical direction. Therefore, the number of attachment steps of the actuator and the number of harnesses for power supply and control increase, which causes increases of space and cost. This is contrary to size-reduction and cost-reduction. Further, in the vehicle lamps provided right and left, the actuators cannot be used in common. This point also causes the increase of cost.
In the vehicle lamp described in JP-A-2005-186731, the two actuators for the two operations are built in the single housing, whereby this vehicle lamp can perform the size reduction and the cost reduction, compared with the vehicle in JP-A-2005-119463. However, since the output part of the actuator for the horizontal rotation and the output part of the actuator for the up-down tilt are respectively located in the separate positions, this double axis actuator can be used in only the lamp unit in which the positional relation between the portions connected to the two output parts is the same. In result, general-purpose properties are poor, and every time the lamp unit is different, a dedicated double axis actuator is required. Further, since the left and right vehicle lamps forms a pair, the dedicated double axis actuator is required for each of the left and right lamp assemblies.
In the vehicle lamp described in JP-A-2003-054310, the above problems in the above two vehicle lamps are eliminated.
However, before one operation, for example, the horizontally rotational operation reaches a limit position, for example, before the lamp unit faces right in front, the tilting operation in the vertical direction cannot be performed. Namely, the operations in the two different directions cannot be independently performed, and the other operation cannot be performed even in case that their operations are put in the any states.
In view of the above problems, an object of the invention is to enable use of a drive unit in many kinds of vehicle lamps thereby to heighten general-purpose properties of the drive unit, enable the independently rotational operations of the lamp unit along two planes orthogonal to each other, and enable the other operation even in case that their operations are put in any states.